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Hydrochlorothiazide and losartan

Hydrochlorothiazide and losartan


Hyzaar combines a new kind of blood pressure medicine (prescribed alone as Cozaar) with an old-fashioned diuretic, hydrochlorothiazide (HCTZ).

It is prescribed for high blood pressure, especially if neither drug alone has lowered blood pressure adequately.

Hyzaar may be less effective for African-American patients.

Side Effects and Interactions

People on Hyzaar have experienced dizziness, weakness, insomnia, muscle cramps or pains, nasal congestion and sinusitis.

Other side effects reported include faintness, low blood pressure, diarrhea, vomiting, indigestion, chest pain and impotence.

Unusual but serious reactions to hydrochlorothiazide include rashes which require medical attention, allergic reactions (anaphylaxis) that involve difficulty breathing and shock, changes in blood, increased blood sugar, and disturbances in the balance of electrolytes.

Periodic blood tests are necessary to check on levels of potassium, magnesium, and other electrolytes. Report any symptoms to the physician promptly.

Dizziness or faintness may be worsened by alcohol, barbiturates, narcotic pain medicine, or dehydration through excess sweating, diarrhea or vomiting. Be especially careful when sitting or standing up.

Hyzaar is not appropriate during the second or third trimesters of pregnancy. If a woman taking Hyzaar becomes pregnant, she should consult her doctor as soon as possible.

The dose of diabetes medicine may need to be adjusted.

Questran and Colestid may reduce absorption of HCTZ and should be taken at a different time of day.

Muscle relaxants and cortisone-like drugs also have the potential to interact.

Arthritis drugs, including OTC NSAIDs like Advil or Aleve, may interfere with the effectiveness of HCTZ.

Lithium is not considered compatible with this diuretic and may become more toxic.

Hydrochlorothiazide alone can make the skin more sensitive to the sun. Avoiding sun exposure or using sunscreen and protective clothing are sensible precautions for those taking Hyzaar.

Tagamet may increase the level of Hyzaar slightly, while phenobarbital reduces it.

Interactions with other drugs such as erythromycin, Nizoral, or Sporanox have not been documented but are theoretically possible because losartan is metabolized by CYP 450 enzymes in the liver.

Licorice can greatly increase potassium loss due to medicines such as hydrochlorothiazide.

Check with your doctor and pharmacist to make sure Hyzaar is safe in combination with any other drugs or herbs you take.

Special Precautions

Hyzaar is not recommended for people with liver disease. Serious kidney problems may also interfere with the safe use of Hyzaar.

Hydrochlorothiazide can aggravate lupus (SLE). Make sure your physician is aware of your health history.

Taking the Medicine

Hyzaar may be taken when convenient, with or without food.

It is taken once or twice a day, according to the prescription.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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